Sea cables are used for providing an electrical connection between offshore facilities such as an array of wind turbines in a wind park or several oil rigs or between off- and onshore facilities. A sea cable connecting two offshore facilities is usually guided vertically from an upper level of a first offshore facility along a pillar of its foundation structure towards the seabed, it is then lead to a course on the sea bed or below the sea bed and it is lastly guided vertically to an upper level of a second offshore facility. In the transition area between an upper level of an offshore facility and the seabed, sea cables are commonly held by means of a support arrangement. It protects the fragile electric leads inside a sea cable against mechanical stress.
A holding apparatus particularly designed for holding a sea cable suspended at an offshore facility is disclosed in EP 1 616 377 B1. An embodiment of this holding apparatus comprises a set of tubes holding a sea cable accommodated within the tubes over a distance between an upper level of an offshore facility and the seabed.
EP 2 158 654 B1 discloses a tubing arrangement for holding a sea cable suspending from an offshore facility towards the seabed by means of a single tube. This tube comprises a J-shaped curved section at its lower end for supporting the sea cable in a transition from a vertical to a horizontal direction.
Both solutions deliver reliable support and protection of a sea cable suspended at an upper level of the offshore facility and being guided to the seabed. The installation of a sea cable within a tubing arrangement according to these disclosures is however difficult. Usually, a sea cable is introduced into a supporting tube from a lower opening of the tube after the tube has been arranged at an offshore facility. As the lower opening of the tube is then positioned below the water surface, the installation requires the use of divers and/or of remotely operating vehicles. This makes the installation process cumbersome and dangerous.